Flue gas denitration device for petrochemical industry and use method thereof

Abstract

The invention belongs to the technical field of flue gas treatment and relates to a flue gas denitration device for the petrochemical industry and a use method thereof. The flue gas denitration device comprises an SNCR reaction unit, a waste heat boiler, an SCR reaction unit, an air pre-heater, an electric dust remover, a desulfurization unit and a chimney which are sequentially connected in a flue gas conveying direction; the SNCR reaction unit comprises a boiler and a spray gun arranged on the boiler, wherein the spray gun is communicated with an ammonia gas source and an air source; the SCR reaction unit further comprises a mixing device arranged at a horizontal section of a flue and an SCR reactor arranged at a vertical section of the flue, wherein the SCR reactor is filled with a molecular sieve catalyst with double active centers, and the mixing device is communicated with the ammonia gas source and the air source; and the desulfurization unit comprises a desulfurization tower. The SNCR and SCR technologies are combined for denitration, the catalyst with double active centers is used for catalysis, and the high-efficiency mixing device is adopted for ammonia supplementation; and thus, the denitration efficiency is high, and the denitration operation cost is low.

Description

technical field [0001] The invention relates to the technical field of flue gas treatment, in particular to a petrochemical industry flue gas denitrification device and a method for using the same. Background technique [0002] Nitrogen oxides, as one of the main air pollutants, are the targets of the country's strict emission control after sulfur dioxide. Coal-fired boilers are the largest source of nitrogen oxide emissions in the petrochemical industry. The nitrogen oxides emitted by coal-fired boilers in the petrochemical industry account for 60-70% of my country's total nitrogen oxide emissions. It is of great significance to reduce oxide pollution and achieve sustainable development. [0003] The most widely used flue gas denitrification technologies are SCR technology and SNCR technology. SNCR technology has low investment, low operating cost, simple system and wide application range, but its denitrification efficiency is low, only 30%-50%, far from meeting the emissi...

AI Technical Summary

Problems solved by technology

SNCR technology has low investment, low operating cost, simple system and wide application range, but its denitrification efficiency is low, only 30%-50%, far from meeting the emission standards. SCR technology has high denitrification efficiency, which can reach more than 95%, but Its denitrification efficiency is limited by the activity of the catalyst. When the SCR equipment is used alone, the service life of the catalyst is short and the operating cost is high.

In addition, when using SCR technology, the uniformity of flue gas and ammonia as a reducing agent directly affects the reduction degree of nitrogen oxides in flue gas. The current denitrification mixing device only passes flue gas and ammonia together. into the mixing chamber, after simple mixing, it is passed into the SCR reactor for denitrification, so that the mixing uniformity of flue gas and ammonia gas is low, which affects the denitrification efficiency

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